Endometrial müllerian carcinosarcoma after cessation of tamoxifen therapy for breast cancer

Abstract

The aim of this report is to draw the attention of clinicians to the possible occurrence of endometrial cancers of rare histological type among women currently undergoing or having in the past undergone tamoxifen therapy, in particular for breast cancer. We report a case of heterologous mixed malignant müllerian tumor occurring in an 80-year-old woman. At 69, she had been diagnosed with breast cancer and received tamoxifen for a total of 55 months over a 6-year period. In the 5th year after cessation of tamoxifen therapy, an endometrial carcinosarcoma was diagnosed. Although the association between tamoxifen use and endometrial cancer is recognized, only a few reports of occurrence long after cessation of therapy exist. We believe ours is the second for this particular histological type. Tamoxifen may have played a role in the occurrence of this tumor although it is also known that this type of tumor may arise de novo in elderly women. The etiologic hypothesis obtained from this case description will now be tested in a formal epidemiological investigation which hopefully will provide more definitive evidence.